Is there an upper limit to battery resistance before deciding to dispose of it?

Batteries and Chargers Rechargeable Batteries
1

Got four protected Keeppower 18650's. They are rewrapped NCR18650GA's with the protection circuit added. They are fairly new but when they have finished charging, resistance is about 100, give or take, for three of the batteries and the fourth is consistently 300 to 320 ohms. Doesn't matter if I clean the terminals, that batteries resistance is always higher. Battery does not overheat, it just takes longer to charge, even when I set termination voltage to 4.1V. Is it still considered safe to use in parallel?

All four batteries were purchased couple of months ago new.

2

If you are going by charger readings, I would not put too much weight in those figures. I haven’t had a cell yet read low . All new from Liionwholesale. Three different chargers. Miboxer considerably high readings.

3

Especially buttontops.

4

Yes button tops. I have to learn one day how to correctly test lions for resistance. Kind of odd that different chargers give different resistance readings.

5

I draw the line at 125

but tons of wiggle room as mentioned.

If it really 3x the others expect it to start acting up soon.

6

Is there any other reliable way to test for resistance that I could do simply?

7

Whenever I start to question “garbage cells”, I pull them from any high-strung lights and stick ’em in something that doesn’t draw too much current, like a headlamp, UV light, etc.

Might as well burn ’em down while the getting’s good, use the good cells in high-strung lights where they’re needed. Ie, you ain’t gonna be taking the Ferrari as a daily-driver to’n’from work, eh? Might as well take the clapped-out Maverick and just run it for as long as it’ll go.

8

Not a bad idea Lightbringer. Right now I have them in my Q8. I could put them in my MF02 as I don't think that is drawing much current on max. Just for fun, I'm going to put that cell in all my chargers that show IR and see what each one reads.

9

And don’t forget to play musical chairs with the cells.

First run is 1/2/3/4. Make the second run 2/3/4/1.

If the 2nd bay always shows higher resistance, it’s to blame. If the high resistance follows the cell, it’s the cell that’s to blame.

Pain in the ass doing multiple runs like that, but sometimes you gotta do it.

10

Another great idea, going to do that now, thank you.

11

Yeah, I’m chock full of ’em…

:laughing:

12

lol. Just tried it in the MC3000. Every slot a different reading and every time I twist the battery in any slot, reading changes again anywhere from 58 to 240. There is are the protected GA's. I think what I should do next time I charge is to load each battery one at a time and twist a little until I get a low IR reading and then load the next battery and do the same. That might be the secret. Just need to press both arrow keys at the same time on the SkyRC, so it's an easy IR test.